Tran, Nhan L.

Abstract Glioblastoma (GBM) is a lethal, treatment-resistant brain cancer characterized by diffuse brain invasion, complex neuron-glioma signaling, and cellular, molecular, and spatial heterogeneity. Surgery is the current mainstay of treatment, aimed at maximizing tumor cytoreduction, decompressing the brain to improve neurological function, and providing material for analyses to inform prognostication and adjuvant treatment selection. To accurately model GBM surgical resection and tissue sampling in preclinical animal models, we developed the Maximal Safe Intracranial Surgery (MSIS) system. MSIS integrated a miniaturized neurosurgical resection device and enabled a safe, tunable, and reproducible approach for intracranial tumor resection, multi-regional biopsy, and longitudinal tissue sampling in murine models, with stereotactic, sterile, and high-viability tissue collection. MSIS was applied across five distinct orthotopic brain tumor models to reproducibly generate histologically and radiologically representative models of post-surgical GBM. Similar to humans, increasing the extent of resection correlated with improved animal survival, and recurrent growth patterns varied significantly by model type. Transcriptional profiles of matched primary vs. post-surgical recurrent tumors revealed enrichment of margin-associated transcriptional states consistent with neuron-glioma signaling. Overall, the MSIS system offers opportunities to model the standard-of-care, dissect the spatial and temporal dynamics of GBM, and pair therapeutic discovery with contextual tumor pathobiology.

Aberrant activation of the Hippo–YAP/TAZ–TEAD transcriptional axis is a recurrent feature of multiple solid tumors and contributes to tumor maintenance, lineage plasticity, and therapeutic resistance. Recent medicinal chemistry has shown that TEAD proteins are druggable, but the rate at which in silico screening nominates compounds that prove functionally active in cells remains poorly defined, and negative validation results are rarely reported. Here we describe an experimental assessment of a focused set of computationally nominated candidate compounds, selected from a structure-guided virtual screen of the YAP–TEAD interface across approximately 917,000 library compounds and three predicted binding sites. Candidates were evaluated using long-term (144 hour) CellTiter-Glo proliferation assays in three Hippo-altered malignant pleural mesothelioma cell lines (MSTO-211H, NCI-H2052, NCI-H226), with the validated TEAD inhibitor K-975 and cisplatin as positive controls, and an exploratory TEAD-responsive luciferase reporter in MCF7 cells. K-975 produced dose-dependent antiproliferative activity in MSTO-211H and NCI-H2052, with reduced sensitivity in NCI-H226, while cisplatin reduced viability in all lines. In contrast, the computationally nominated compounds, including AG-690/36549045, AN-655/40856217, and additional library members, did not produce measurable antiproliferative activity at the concentrations tested. In the exploratory reporter, apparent suppression of TEAD activity consistently co-occurred with loss of cell viability, a pattern consistent with cytotoxicity rather than selective transcriptional inhibition; no TEAD-active reference compound was co-tested within the reporter panel, and no direct YAP–TEAD biochemical or target-engagement assay was performed. These results describe a case in which computational nomination at the YAP–TEAD interface showed limited concordance with cell-based activity and provide a transparent account of negative findings to inform expectations for early-stage discovery targeting Hippo-dependent transcriptional programs.

Abstract Introduction Immunotherapy approaches against glioblastoma (GBM) such as immune checkpoint inhibitors (ICI), dendritic cell vaccination, and CAR-T have failed to durably cure most patients. Studies analyzing tumors from ICI responders show that abundance of CD4 and CD8 T cells prior to initiation of therapy predicts responsiveness. Thus, targeting the microenvironment to promote CD4 activity may synergize with ICI. The glioblastoma microenvironment contains high proportions of monocyte-derived macrophages which have potent immunosuppressive capabilities. Characterizing and targeting these immunosuppressive programs is a promising strategy for designing effective combination immunotherapies for glioblastoma patients. Methods We analyzed human glioblastoma snRNAseq datasets to find signaling receptors associated with myeloid immunosuppression and employed murine models of glioblastoma for functional validation. Results By analyzing patient-derived -omics datasets, we identified an understudied TNF-superfamily receptor, Fn14, as being upregulated in glioblastoma-associated myeloid cells with immunosuppressive gene signatures. Using in vitro approaches, we found that Fn14 activation in the tumor microenvironment can drive cytokines implicated in GBM immunosuppression such as IL6, IL1B, and IL8. Thus, Fn14 may serve as a surface marker for microenvironment-remodeling myeloid cells recruited to the tumor from peripheral circulation. Furthermore, in murine models of glioblastoma, we discovered Fn14 KO among glioblastoma-associated myeloid cells increases conventional dendritic cell type 1 (cDC1) and Th1 CD4+ T cell abundance in the tumor microenvironment and significantly prolongs survival. Conclusion These results suggest that blocking Fn14 in glioblastoma-associated myeloid cells can enhance Th1 immunity. Thus, Fn14 may represent a promising dual therapy target. Funding Source NIH Topic Categories Tumor Immunology: Cellular Responses and Tumor Microevironment (TIME)

Abstract Background Glioblastoma (GBM) remains a devastating cancer with limited treatment options, largely due to its heterogeneity. While supramaximal resection has recently provided survival benefits, therapeutic profiling of different tumor compartments, particularly its infiltrative edge remains largely unexplored. Methods Here, we leveraged magnetic resonance imaging (MRI)-guided multi-sampling, collecting 2 cores and 2 margins per case, to query GBM heterogeneity. Whole-exome and RNA-seq with drug testing in two patient-derived 3D models were used to reveal similarities and differences in genomic and transcriptomic makeups, cellular compositions, and drug responses across cores and margins. Bioinformatics interrogations further identified response biomarkers. Results Mutation analysis showed that oncogenes exhibited a higher degree of spatial heterogeneity than tumor suppressor genes, regardless of MRI status. While the mesenchymal transcriptional subtype with extracellular matrix remodeling, stress response, and immune programs were preferentially enriched in enhancing cores, proneural tumors with neurological processes favored non-enhancing margins. Using a 15-drug GBM-targeted panel, ERK (ulixertinib) and PI3K pathway (paxalisib, CC-115) inhibitors showed preferential efficacy in enhancing cores and non-enhancing margins, respectively. The anti-apoptosis, pan-Bcl2 agent navitoclax and the epigenetic drug trotabresib represented the most effective, tumor-wide monotherapies. Importantly, drug combinations generally outperformed single agents across all regions. Conclusions This work demonstrates the regional heterogeneity of therapeutic vulnerabilities in GBM ex vivo, showing various drugs with tumor-wide or MRI-enhancement informed activity. These findings offer preclinical bases of numerous monotherapies and drug combinations for future clinical trial design.

Abstract Background Glioblastoma (GBM) is driven, in part, by glioma stem cells (GSCs), which sustain therapeutic resistance and recurrence. OLIG2 is a key regulator of GSC programs but the signaling pathways that cooperate with Oligodendrocyte transcription factor 2 (OLIG2) to maintain GSC states remain incompletely defined. Although Signal transducer and activator of transcription (STAT) signaling has been implicated in GSC biology, work to date has focused primarily on STAT3, and the contribution of STAT5 remains poorly defined. Here, we investigated whether STAT5B functionally cooperates with OLIG2 in sustaining GSC phenotypes. Methods Transcriptomic analyses, proximity ligation assays and biochemical studies were utilized to define OLIG2-STAT5B interactions in patient-derived GSCs. Functional consequences of OLIG2, STAT5B, BIRC5, and NUSAP1 suppression were assessed using small interfering RNA/short hairpin RNA-knockdown, stemness, and migration assays in EGFRvIII-expressing GSCs. In vivo tumor growth studies were performed using orthotopic xenograft models. Results OLIG2 and STAT5B expression were positively correlated in GBM datasets and patient-derived models. OLIG2 physically associated with STAT5B in EGFRvIII-expressing GSCs, and loss of OLIG2 reduced STAT5 activation, supporting a functional link between these factors. OLIG2 or STAT5B suppression induced convergent transcriptional changes, including downregulation of genes associated with GSC maintenance and proliferation, notably stemness regulators BIRC5 and NUSAP1. Silencing BIRC5 or NUSAP1 impaired GSC self-renewal and migration. In orthotopic models, STAT5B knockdown prolonged survival and phenocopied OLIG2 suppression and stemness loss. Conclusions These findings identify STAT5B as a functional partner of OLIG2 in GBM and define anOLIG2-STAT5B transcriptional axis that sustains GSC maintenance and malignant behavior. Targeting this axis may represent a therapeutic strategy to disrupt treatment-refractory glioma cell states.

Background/Objectives: KRAS G12C mutations define a clinically actionable subset of solid tumors, particularly non–small cell lung cancer. Clinical responses to approved covalent inhibitors remain limited by intrinsic and acquired resistance, highlighting the need for structurally distinct inhibitor scaffolds to expand therapeutic options. The objective of this study was to identify novel covalent binders targeting the KRAS G12C switch-II pocket through large-scale in silico screening and experimental validation. Methods: More than 1.9 million small molecules from diverse commercial libraries were screened using covalent docking, followed by multi-stage refinement incorporating molecular dynamics simulations, MM/GBSA free-energy estimation, and cancer-focused QSAR modeling. Results: This integrated workflow yielded 50 prioritized compounds spanning several chemically distinct scaffold classes. These candidates displayed favorable predicted binding energetics, stable ligand-protein interactions over extended simulation timescales, and low structural similarity to clinically approved KRAS G12C inhibitors sotorasib and adagrasib. Benchmarking against these clinical agents, using identical computational parameters, yielded comparable predicted binding energies for several candidate molecules. In cellular NanoBRET target-engagement assays, selected scaffolds, including K788-7251 and AN-989/14669131, exhibited sub-micromolar engagement of KRAS G12C with minimal endothelial cytotoxicity. Conclusions: Collectively, these findings identify structurally distinct, KRAS G12C inhibitor chemotypes and provide tractable starting points for the development of next-generation targeted therapies.

Abstract Purpose: Despite advances in molecular diagnostics, glioblastoma (GBM) remains incurable, with recurrence driven by residual invasive tumor cells that escape surgical resection and therapy. Current genomic profiling to guide therapy for recurrent disease typically relies on a single-site clinical biopsy (SSCB) obtained from the contrasting-enhancing (CE) tumor core - the region targeted for maximal resection and most visible on Magnetic Resonance Imaging (MRI). However, this region poorly represents the non-enhancing (NE) invasive tumor margins, which harbor treatment-resistant and genetically distinct cell populations responsible for disease recurrence. GBM exhibits extensive spatial heterogeneity, raising concerns that a single tissue may underrepresent the true actionable landscape of the tumor. Experimental Procedures: We analyzed 302 biopsies from 66 GBM patients who underwent multiregional whole exome and RNA sequencing across CE and NE tumor regions. Of these, 17 patients also had standard-of-care SSCB molecular profiling utilizing clinically available genomic sequencing panels outside of the multiregional protocol. Variants that have been targeted in ongoing or successful human clinical trials were annotated as actionable. We compared actionability profiles between SSCB and multiregional sampling, to determine the gain of actionable variant detection across the two sampling strategies. We performed an in-silico biopsy simulation to model the coverage of these alterations across the tumor landscape with increasing sampling frequency in the multiregional protocol, versus the coverage from clinical sequencing panels on SSCBs. Results: Clinical sampling identified a median of one actionable mutation per patient (range 0-3). In contrast, multiregional profiling revealed additional potentially actionable variants in over 70% of patients, particularly within NE infiltrative regions that are not captured by conventional resection. Notably, nine potentially actionable copy-number variants, including PDGFRA amplification, were consistently absent from SSCB results and underrepresented in most clinical panels. In silico biopsy simulations demonstrated that actionable variant detection continues to rise even after sampling five additional regions, reflecting spatial segregation of therapeutic targets. Conclusions: These findings demonstrate that a single sample from the CE tumor core fails to capture the biologically diverse invasive tumor populations responsible for GBM recurrence. Multiregional sequencing uncovers clinically meaningful alterations that would otherwise remain undetected with conventional sampling, highlighting the risk of incomplete molecular characterization in current clinical biopsy workflows. Citation Format: Enmar Harfoush, Taylor Weiskittel, Mylan Blomquist, Dustin Grief, Aadel A. Chaudhuri, Leland S. Hu, Nhan L. Tran, Shannon Fortin-Ensign. Beyond a single core biopsy: Spatial genomic profiling improves therapeutic target detection in glioblastoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2026; Part 1 (Regular Abstracts); 2026 Apr 17-22; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2026;86(7 Suppl):Abstract nr 706.

Abstract Enhancer is a critical epigenetic feature in head and neck squamous cell carcinoma (HNSCC), yet the functional roles of individual enhancers remain poorly understood. Here, we conducted an integrative multi-omics analysis based on publicly available ATAC-seq, H3K27ac ChIP-seq, transcriptomic profiling, and genetic association datasets to systematically map HNSCC-associated enhancers and their target genes. Integrating ATAC-seq and H3K27ac ChIP-seq, we identified 20,362 enhancers and 18,040 enhancer-associated genes, highlighting widespread regulatory complexity. Functional characterization of the TERT -associated enhancer GH05J001312 (GRCh38/hg38: chr5:1312099-1317743) revealed strong transcriptional activity in HNSCC. CRISPR-mediated deletion of a core sequence significantly reduced TERT expression, impaired cellular proliferation in vitro , and suppressed tumor growth in vivo , confirming its role as a key cis-regulatory element. RNA-seq analysis of enhancer-edited cells uncovered 742 differentially expressed genes enriched in cancer-related pathways, including MAPK and IL-17 signaling, indicating a broad transcriptional impact. Collectively, our findings establish GH05J001312 as a functional enhancer driving oncogenic programs in HNSCC and suggest enhancer-targeted strategies as a potential therapeutic avenue.

Abstract Background Fibroblast growth factor-inducible 14 (Fn14) belongs to the TNFR superfamily. Fn14 overexpression can drive receptor-autonomous signaling, increase both cell invasion and tumor-associated macrophages/microglia (TAMMs) recruitment, and correlates with reduced survival in glioblastoma (GBM) patients and rat gliomas. While prior studies report Fn14 expression in non-tumor cells within the GBM tumor microenvironment (TME), their relative contributions to glioma pathobiology remain unclear. Methods Using tumor-host pairings of Fn14-positive and -knockout (-KO) cells and mice, we examined the role of Fn14 in glioma biology. Mouse glioma and human GBM datasets were analyzed at the cellular, protein, and transcriptomic levels to assess Fn14-associated changes in the glioma TME and survival outcomes. Results Fn14 was found to be highly expressed in tumor cells and TAMMs in human GBM and 2 well-characterized murine glioma models. Fn14 KO in both tumor and host cells increased overall survival. Notably, this survival benefit was greater in the glioma model characterized by a more immunologically activated TME. Immunophenotyping revealed that Fn14 loss reshapes the tumor-immune landscape, reducing the presence of immunosuppressive macrophages and exhausted T-cells, suggesting that Fn14 modulates both innate and adaptive immune responses. These findings were supported by analyses of human GBM datasets, where high Fn14 expression correlated with immunosuppressive shifts and poor patient responses to immune checkpoint inhibitor therapy. Conclusions This study provides the first description of the contributions of both tumor- and host-derived Fn14 expression to tumor immunity and survival and identifies Fn14 as an important mediator of innate and adaptive immune responses in gliomas.

Abstract Lung cancer is the leading cause of cancer-related deaths worldwide, and despite advances in treatment, immune suppression remains an obstacle to effective therapy. Effector CD4+ T cells (CD4+ Teff) are critical for antitumor immunity, but their function is often inhibited by regulatory T cells (Treg), which accumulate in lung tumors and mediate suppressive functions through multiple mechanisms. This suppression leads to tumor progression and poor patient outcomes. However, the mechanisms underlying Treg-mediated suppression are not fully understood. Herein, we identify the extracellular adenosine 5-triphosphate receptor P2RX7 as a key regulator of Treg function in lung tumors. In a murine lung cancer model induced by Lewis lung carcinoma cells, we found that P2RX7 enhanced the suppressive capacity of tumor-infiltrating Tregs, promoting tumor growth. In T cell–specific P2RX7-knockout (P2RX7-KO) mice, reduced Treg infiltration was accompanied by increased CD4+ Teff accumulation and improved tumor control. Treg-specific P2RX7-KO mice exhibited reduced tumor growth, confirming a Treg-intrinsic role of P2RX7. Suppression assays revealed that tumor-infiltrating wild-type Tregs had greater suppressive activity compared with P2RX7-KO Tregs, which failed to inhibit type 1 and follicular helper T–like responses. This was associated with increased tumor-specific IgG production by lung B cells in P2RX7-KO mice. We also observed that wild-type Tregs expressed higher levels of the immunosuppressive molecule CTLA-4 when compared with P2RX7-KO Tregs. Thus, we conclude that P2RX7 expression on Tregs is essential for their suppressive function in lung cancer and targeting P2RX7 may constitute a strategy to improve lung cancer treatment by alleviating Treg-mediated immune suppression.